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(No Model.) 2 Sheets-Sheet l.

W, M. WOOD.

METHOD OF MANUFACTURING PROJEGTILES BY ELECTRIC WELDING.

No. 424,441. Patented Mar. 25, 1890.

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(No Model.) 2 sheets-Sheep 2. W. M. WOOD. METHOD OF MANUFACTURING PROJEOTILES BY ELECTRIC WELDING Patented Mar. 25 1890.

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UNITED STATES PATENT OFFICE.

\VILLIAM M. \VOOD, OF \YASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE THOMSON ELECTRIC IVELDING COMPANY, OF BOSTON, MASSA- CHUSETTS.

METHOD OF MANUFACTURING PROJECTILES BY ELECTRIC WELDING.

SPECIFICATION forming part of Letters Patent No. 424,441, dated March 25, 1890.

Application filed November '7, 1889. Serial No. 329,506. (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM M. Woon, a citizen of the United States, and a resident of Washington, in the District of Columbia, have invented a certain new and useful Method of Manufacturing Projectiles, of which the following is a specification.

My invention relates to the process of manufacturing hollow shells or projectiles adapted for use in warfare, and is particularly applicable to the manufacture of armorpiercing projectiles, which are made hollow to hold a bursting charge.

The object of my invention is to do away with the difficulties incident to the methods of manufacture at present in use for making projectiles, to lessen the cost, and to facilitate the manufacture.

A further object of my invention is to produce a finished projectile of low cost, but of high strength and efliciency.

The process of manufacture at present ordinarily employed in making projectiles involves either the casting of the point and hollow body in one piece, the base of which is subsequently filled by a plug through which the fuse passes, or the making of a solid ingot or body of metal which is turned out to form the chargechamber. The latter method,

0 especially when used in making projectiles of hard high-carbon or chrome steel, is difiicult'and costly, while in the case of cast hollow projectiles great skill in casting is required in order to obtain accuracy of form or 3 5 thickness in the walls of the projectile.

My invention consists, essentially, in forming the hollow body of the projectile as a separate tubular section, separately forming the point of the projectile, and then welding the 40 two together by the electriewelding process. The point-section may be entirely solid, but preferably has a rather shallow depression forming the forward end of the chamber containing the charge. The body-section is preferably formed as a tube open from end to end, andis preferably constructed from a section of drawn tubing of homogeneous metal, though it might be made by swaging, expanding, or reaming out a hollow piece of metal, or by any other method which will give the hollow tubular section for the body of the projectile with walls of the proper thickness and proportion made in a single piece. By this process of manufacture for making armor-piercing shell, or other kinds of shell I dispense with all boring into the solid metal (which is usually a high-carbon or chrome steel) to form the required cavity for the bursting charge. Again, as the head and body are made separately, each section admits of more exact manipulation, being easier to wield and allowing of more ready use of tools, thereby insuring greater accuracy of form, weight, and relative proportion.

In making the body of the shell I preferably use a piece of drawn tubing, since the inner and outer skin or fibrous surface due to the drawing of the metal adds greatly to the strength of the projectile throughout the body and weakest parts. The base end of the body I also preferably make separate from the body itself and weld it to the body section.

My invention consists, further, in acertain improved process of manufacturing a proj ect- 7 5 ile with a rotating band, as will be hereinafter more fully explained.

I11 the accompanying drawings, Figure 1 shows in longitudinal section the three pertions of a common shellto wit, the point, body, and base-as completely formed preparatory to beiu g electrically welded together. Fig. 2 shows in perspective the complete manufactured shell. Figs. 3 and 4. show the three sections of an armor-piercing shell, detached in Fig. 3 and joined in Fig. at. Fig. 5 is a side elevation and partial section of a portion of an electric-welding apparatus that may be used in practicing my invention. Fig. 6 is a cross-section through the same on the line a; 00, Fig. 5. Fig. 7 shows a modification in the form of one of the holders of the electrio-welding apparatus. Fig. 8 is an end elevation of the upperpart of the apparatus, Fig. 5. Fig. 9 is a similar view of an apparatus 95 in which a modified construction of clamp is employed.

Referring to Fig. 1,A indicates the head, B the body, and C the base, of a common shell, arranged in the order in which the parts are joined to form the complete shell. The head A, of the usual ogival form, is made by any desired orconvenientprocessas,for instance, by casting or by any other process, as dropforging, rolling, hydraulic pressure, or other process employed in metal-working. It will be obvious that the point-section may be made to embrace a greater or less part of the charge-space, or none at all, as desired. If, however, it is wished to form a strengthening burr or projection on the interior of the shell, the point should embrace a greater or less part of the charge-space. The body B is made separately for union to the head, and as a single homogeneous piece of metal, which may embrace the base 0, but is preferably made as a tubular section open from end to end. By so making it I am enabled to use drawn tubing for the body of the projectile, or if the body should be cast I am enabled to secure accuracy of form and distribution of metal, since the core may be held oreentered firmly in the process of casting. The base 0 of the shell is formed separately from the body in any desired manner.

After forming the several parts I unite them by end pressure applied in the process of electric welding, as will be hereinafter more fully described In the case of an armor-piercing shell, such as shown in Figs. 3 and a, the head, of the usual ogival form and of the requisite or usual thickness of walls, may be made by drop forging, rolling, hydraulic pressure, stamping, or other usual methods. The body of the shell may be made of drawn tube of homogeneous metal and of the same metal as the head, or it may be made of short sections of suitable metal swaged, expanded, or reamed out, or by any method by which the interior cavity may be made of the proper shape and to give the walls the proper thickness and proportion. The base of the shell may be of the same thickness as the body and may be stamped out or flanged up or otherwise made and provided with a suitable fuse-hole. By thus making the base portion of the projectile I amenabled to furnish a projectile having an unbroken outer surface when the parts are welded together, which need only be pierced through the center of the base or point, as the case may be, when it is necessary to introduce a fuse.

Heretofore, in making forged projectiles it has been usual to leave the end open at the base and afterward to close it up by a large plug, which itself may be pierced for the fuse. Such a structure is obviously much weaker than one in which the base is stamped up or otherwise formed as a solid piece united by welding, as hereinafterdescribed, to the body portion and subsequently pierced by an opening only sufficient to admit a fuse.

To apply a rotating band D, I form the several sections in transverse lines correspondingto the desired location of the band I) and turn down or provide the end of the section with an offset, as indicated, to which the band maybe applied before the sectionsare joined together. Hitherto the practice has been to force the band into position over the base and body of the shell by the application of great pressure, which necessarily strains the band. The point and body, with the base formed as indicated, are now joined by the process of electric welding in any suitable apparatus-such, for instance, as that indicated in Figs. 5 to 9, wherel have shown one of the forms of welding apparatus suitable for the purpose.

E is a heavy bar or mass of copper having a groove or recess in its side, in which lies a coil of insulated wire F. The bar E is the secondary and F the primary of a converter or induction-coil by which electric currents of great volume and low electro-motive force may be developed when an alternating electric current from any suitable machine or other source is passed through the primary F, as well understood in the art.

Sheets or plates of iron (indicated at T) are applied to the secondary bar E for the purpose of forming an iron core and assisting the inductive action. These sheet-iron pieces may be made in one or more parts and fastened together over the secondary.

Mounted on the ends of secondary E and in electrical connection therewith are the copper blocks or bearings G II, which support the parts to be Welded. Block G may be provided with a step or seat adapted to receive the base C, and with a clain 'iiug-lever 1, eperated by a screw, as shown, and adapted to hold 0 firmly connected to its support. Clamp-block II has a movable clamp-plate K and fastening-bolts, both clamp and plate being suitably conformed to the section of projectile to be held by them. For holding the head or point of the projectile a clamp like II K might be used where the head or pointsection is long enough to embrace a part of the cylindrical portion of the'projectile, or the clamp or holder might be a solid block, as in Fig. 7, having a cavity conformed to the head and perforated at its rear to admit a rod for dislodging the work after the welding operation.

For holding the tubular or round section of the projectile, whether solid or hollow, it is preferable to employ a clamp like that in Fig. 9, where the clamping devices are shown divided in a vertical line, so that both parts are in electrical connection with the secondary directly and the current is more evenly distributed in the work. In the form shown in Fig. 8 the upper plate K can only receive current through the work, and the clan1p-screws and the upper part of the tubular section are therefore liable to heatless rapidly than the lower. The clamp-body ll moves on suitable guides 011 bar or block E and can be forced toward its opposite clamp by means of a screw L.

The several parts of the projectile having been first properly formed, as described, to

fulfill their several requirements, they are placed in their proper position in the clamps of the electric-welding apparatus with the ends of the sections abutted, and a heating current of electricity is applied of a volume and for a length of time suflicient to raise the parts in contact to a welding temperature. Endwise pressure is then applied in the man ner well known in electric welding to complete the union. The eitect of this endwise pressure, it the ends of the sections in abutment have not been specially formed, will be to raise a burr or enlargement on the interior and exterior of the shell.

In the case of armor-piercing shells the inside burr or projection formed, as indicated at m, Fig. 4:, by the pressure which operates to crowd the metal inward beyond the plane of the interior surface has an important function in strengthening the projectile at the point where it is subjected to great strain and liability of fracture when it strikes armorplating. The burr which would be formed on the exterior of the shell, Fi 1, may be ground to fit the exact bore of the gun, and may then serve the purpose of the so-called bourille or enlargement now used for the purpose of centering the head of the projectile in the If it be desired to prevent or diminish the bur or projection, the edges where the sections meet for welding may be beveled, as indicated in the dotted lines, or to throw the burr outward and preserve the shape of the interior cavity the bevel may be from the inside outward, as indicated. 1 might also employ a mandrel of any suitable material, as iron, but preferably a material which is a bad conductor of heat or a poor conductor of electricity to preserve the shape of the interior cavity.

It is obvious that the pieces composing the projectile may be either steel or iron, or both, or any metal or combination of metals which are capable of being joined together solidly by Weldin It is evident that this process of manufacture of hollow projectiles can be applied to the construction of other forms of projectiles besides those shown.

By the process hereinbefore described of manufacturing projectiles I am enabled to produce projectiles which shall be practically entirely finished on the completion of the welding operation. This result is especially feasible if the body of the projectile be made of a drawn tube or cylinder. The methods of manufacture at present in vogue for making projectiles require that the projectile shall be finished or dressed 01f to complete the manufacture.

I do not claim herein a novel construction of hollow projectile made with a hollow body section welded to the point-section, nor do I claim herein the other novel features of construction which may be attained by my process, as these all form the subject of another application for patent filed by me November 7,1889, No. 329,507.

I am aware that it is old to employ the electrio-welding process for joining sections of tubing or pipe together. My present invention relates to an improved process of making projectiles, and the electric welding process is employed by me-only as a part of the process constituting my invention.

A projectile having a bourillet made as herein described and the manner of manutacturing the same are not herein claimed, as they form the subject of claims in an application for patent filed by me January 11, 1889, No. 338,497.

hat I claim as my invention is-- l. The hereindescribed improvementin processes of manufacturing hollow proj ectilcs, which consists in forming the body as a separate tubular section, separately forming the point, and then welding the two together by the electric-welding process, as and for the purpose described.

2. The hereindescribed improvement in processes of manufacturing hollow metal projectiles, which consists in making the body portion from drawn tubing and separately from the base and point, swaging, pressing, or otherwise forming the point and base into the desired shapes, and then electrically welding the hollow body to the said point and base, as and for the purpose described.

3. The herein-described improvement in making hollow metal projectiles, which consists in making the body portion separately from the point, forming thepoint-section with an internal cavity, placing the two together in an electricqvelding apparatus, and then subjecting the same to endwise pressure, so as to raise a burr or projection at the point of union, as and for the purpose described.

at. The herein described improvement in manufacturing hollow projectiles, which consists in forming the base as a closed cupshaped body closed at its bottom or end, welding the same to the body by the electric-welding process, and either before or after such operation piercing the end with the fuse-hole, as and for the purpose described.

5. The herein-described improvement in making hollow projectiles, which consists in forming the body from drawn tubing and then welding the same to the head by the electricwelding process, as and for the purpose described.

6. The hereindescribed improvement in making projectiles, which consists in finishing the body portion separately from the head, with an inner and outer skin, and then welding said. point and head together by the electricavelding process, as and for the purpose described.

'7. The herein described improvement in manufacturing projectiles having a rotating band, consisting in forming the same in sec- York and State of New York, this 5th day of tions with the line of union at the point of November, A. D. 1889. application of the band, putting the band in place with the sections abutted, and Welding 5 said sections together, as and for the purpose described.

WILLIAM M; WOOD. WVitnesses:

J. S. HURDLE,

Signed at New York, in the county of New 7M. I'I. CAPEL. 

